Push-drill.



Patented July 23, 1912.

W. A. PECK.

PUSH DRILL. APPILIOATION FILED DEG. 23, 1911.

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an Mm UNITED STATES PATENT OFFICE.

WILLIAM A. PECK, OF NEW HAVEN, CONNECTICUT.

PUSH-DRILL. l

Specification of Letters Patent.

Patented July 23, 1912..

Application filed December 23, 1911. Serial No. 667,520.

erence marked thereon, to be a full, clear,

and exact description of the same, and which said drawings constitutepart of this specification, and represent, in-

Figure 1 a View in side elevation of a push-drill constructed inaccordance with my invention. Fig. 2 a view thereof in centrallongitudinal section. Fig. ,3 a detached view in side elevation of thepowerspring and spring-carrier shown at a right angle to the positionsin which they are shown in Fig. 2.. Fig. 4 a detached plan view of thedrill-bit. Fig. 5 a detached view partly in side elevation, and partlyin section, of the chuck, Fig. 6 a view in longitudinal central sectionon an enlarged scale of the reversible chuck-jaws, shown at a rightangle to the position in which they are shown in Fig. 5. Fig. 7 adetached view in elevation of the reversible chuckjaws shown in fulllines as holding a brad, and in broken lines as holding a drill. Fig. 8a view in inside elevation of one of the reversible chuck-jaws showingthe co-action between the depending stop-finger of the abutment-blockand the stop-finger formed upon the shank of the drill-bit. Fig. 9 adetached perspective view of the abutmentblock. Fig. 10 a detached viewin side ele vation of one of the drill-bits. Fig. 11 a detached view inside elevation of a wire brad such as my improved push-drill is adaptedto insert, and leave in position for being driven home. Fig. 12 a brokenview in longitudinal section showing the modified form of the meansemployed for adjusting the tension of the power spring.

My invention relates to an improvement in that class of hand-boringtools known as push-drills, the object being to produce a push-drill ofsuperior simplicity, durability, convenience and efiiciency, withparticular reference to the regulation of the tension of itspower-spring, and to adapting the drill to be used for the insertion ofordinary wire brads.

With these ends in view, my invention consists in a push-drill havingcertain details of construction and combinations of parts as will behereinafter described and pointed out in the claims.

In carrying out my invention as herein shown, I employ a long helicalpowerspring 2 having a coupling-plug 3 inserted into, and fixed withinits outer end, this coupling-plug being furnished with a blade 4entering a transverse slot 5 formed in a coupling-block 6 fixed withinthe center of the outer end of the cup-like hand grip 7 of the drill.the said power-spring 2 receives a bearingplug 8 which is maintainedin-constant engagement with, and turns upon, the inner end of the stem 9of the bifurcated body or At its opposite or inner end core 10 of thedrill chuck, the said body or core being formed with external threadsfor the application and adjustment of the chuck-sleeve 11 which operatesthe reversible chuck-jaws 12, which will be described,

The said power-spring 2 is lolater on. cated within the tubular body ordriving member 13 and the tubular chuck-carrier or driven member 14 ofthe drill, with the exception of its passive outer end which extendsinto the hand-grip 7, it being understood that the driving-member 13 andthe driven-member 14 are telescoped one within the other against thetension of the spring 2 by endwise pressure applied by the user of thedrill, whereby the driven member 14 Y is in position to be again drivenback into the driving-member when the user of the drill again appliesendwise pressure thereto in the ordinary manner. In this connection,

it may be explained that the driven-member let is furnished at its outerend with coarsely pitched screw threads 14 which pass through acorrespondingly grooved nut 15 fixed within the tubular driving-member13, whereby rotary movement is imparted to the drivenanember orchuck-carrier 1 1.

Coming now to the chief feature of my present invention, it is necessaryto provide for the regulation of the tension, of the power-spring 2 inorder to adapt the pushdrill to be used to the best advantage with drillbits varying in size and in drilling wood or other objects varying indensity or resistance. For this purpose I vary the tension of the springby virtually changing the length of it by varying the number of itscoils in active use at any one time.

For the purpose above described, I provide, as herein shown, aspring-regulation abutment in the form of a pin 16 passing between thecoils of the said power-spring 2 at a right angle to the longitudinalaxis thereof, and fixed at its ends within a housing-tube 17 locatedwithin the driving-member 13. The said tube 17, which is a trifle largerin diameter than the diameter of the spring 2 and controls any tendencythat the same may have to buckle in its middle portion, is held in placeby being furnished with an externally threaded collar 18 which isscrewed into a collar 19 fixed upon the outer end of the driving-member18 and furnished with a set screw 20 impinging against the collar 19. Apin 21. corresponding to the pin 16, but arranged at a right anglethereto in the housing tube 17, takes up, so to speak, the back-lash ofthe passive outer end of the power spring 2 and prevents the same fromturning with respect to the pin 16 in the use of the push drill, sinceit is conceived that in the constant operation of the device the powerspring 2 mightbe jarred back to a certain extent after being onceadjusted. The coils of the power spring 2 in front of the pin 16 arealone compressed in operating the drill, and hence form the operative oractive portion of the spring while those coils of the spring that lieabove the said pin 16 are left inert and form the passive portion or endof the spring which I shall hereafter speak of as having active andpassive ends separated by the pin 16 or its equivalent. It willtherefore be understood that the in 16 virtually divides the powerspring 1nto an active and a passive portion since in the operation ofthe device the only portion of the spring that is placed under tensionis that portion of it in front of the pin 16, while the portion of itback of the pin 16 is left passive so far as the operation of the drillis concerned. It follows from this that the power of the spring at anytime depends upon the number of coils of the spring that are in front ofthe pin 16 and therefore available for compression in the use of thedevice. Therefore all that is necessary to do for the regulation of thepower of the spring 2 is to bodily turn the spring with reference to thepin 16 so as to increase or decrease the number of its coils ahead ofthe pin 16.

For turning the power-spring 2 bodily in either direction as may berequired for in creasing or decreasing the power supplied by it for theoperation of the push-drill, the hand-grip 7 is rotated in one directionor the other, the said hand-grip being coupled with the spring by meansof the couplingplug 3 and block 6 already described.

The hand-grip 7 is normally locked against rotation by means of a dog 22having its outer edge serrated and located in a recess 23 formed in theperiphery of the cylindrical drill-bit magazine 24, the shank 25 of thedog entering a bore 26 leading out of the bottom of the recess 23 andreceiving a small helical spring 27 which exerts a constant effort topush the dog outward and enter its outer end into a locking-notch 28 inthe adjacent edge of the hand-grip 7, the said dge of which, as I mayhere point out, bears upon the edge of the flat upper face of themagazine 24. The said hand grip 7 is fastened to the driving-member 13by means of a set-screw 29 mounted in one of the side walls of the gripand entering a circumferential groove 30 in the outer face of the collar19 which, as aforesaid, is permanently fastened to the outer end of thedriving-member 13.

The cylindrical drill-bit magazine 21 corresponds in diameter to thediameter of the hand-grip 7 and is fastened to the drivingmember 18 bymeans of a set screw 31 as seen in Fig. 2. As shown, the magazine 24: isformed with a circular series of bit-receiving pockets 32 consisting ofalternately arranged grooves and holes, but the particular adaptation ofthe magazine for the reception of the drill-bits may be varied asdesired. The bits are stopped from longitudinal outward movement by theadjacent edge of the collar 19 and are held against inward displacementby means of a magazine cover 38 the outer edge of which fits snugly overthe inner edge of the magazine, while its inner end is rounded andadapted to bear, as shown in Fig. 2, upon the periphery of thedriving-member 18. The cover is held in place by its provision with abayonet slot 34 receiving a pin mounted in the periphery of the magazine24.

A knurled plug 86 mounted in the inner end of the driving-member 18provides a stop for the outward movement of the tubular driven-member 14under the power of the spring 2, the threaded sleeve 37 of the plug 36forming a shoulder for co-action with the inner ends of the coarse screwthreads 14 before mentioned.

The reversible jaws 12 of the chuck are adapted to be reversed end forend in the bifurcated chuck-body 10 for the purpose of adapting thepush-drill to be used with ordinary drill-bits like the bit 38, or to beused for inserting ordinary wire brads like the wire brad 39,preparatory to being driven home. Each jaw 12 is formedat a point to oneside of its longitudinal center with a recess 40, these recesses beinglocated opposite each other and receiving a steel abutment-block oranvil 41 traversed by a circular transverse passage 42 receiving ahelical spring 43 which in turn receives a long coupling-pin 44 theouter ends of which are headed down upon the outer face of therespectlve aws, whereby the same are coupled together, but normally heldslightly separated from each other by the spring 43 the ends of which bybearing upon the bottoms of the said recesses 38 exert a constant effortto hold the jaws apart in position for the reception between them of theshank of a drill-bit or the head of a wire brad, as the case may be. Thelonger ends of the jaws are formed with the usual'complementary grooves45 for the reception of the shanks of the bits which are held againstturning by their provision with, stop-wings 46 co-acting with astop-wing 47 offsetting from the inner end or bottom of the abutment 41which forms an endwise stop for the drill bits.

The shorter ends of the jaws are formed with short V-shaped grooves 48adapted to grip brads adjacent to their heads for which clearance ismade by cutting away the jaws adjacent to the outer end of the saidabutment or anvil 41, to form a small clearance opening 49 just largeenough to receive the head of a brad. A brad being grasped adjacent toits head, but not by its head, is inserted into the woodwork, whateverits character may be, in precisely the same manner as a drill bit wouldbe inserted into the woodwork. Then when the chuck-jaws are loosened andthe push-drill removed, the brad will be found sticking out of thewoodwork for a distance represented by the length of the head and somuch of the brad as was gripped by the jaws. In this position the bradcan be driven home with a hammer without any danger of bending the brad.At this point I may say that in inserting brads it is necessary tooperate the push-drill wit-h the spring at a light tension since thereis no temper in the ordinary commercial brad. By providing my improvedpush-drill with a power-spring easily regulated in tension and withreversible chuck-jaws, I endow it with the unusual function of insertingordinary brads. For the reversal of the chuck-jaws 12 end for end, it isnecessary merely to remove the 50 when swung back exposes the outer endof the power-spring 2 which may then be seized by the fingers and turnedin one direction or the other, or the said spring may be adjusted bygripping the knurled stem 51 of a nut 52 mounted so as to be rotatablein the outer end of the driving-member 53 of the device and held inplace by a set screw 54 entering its circumferential groove 55. The saidnut 52 is formed with an internal spiral groove (not shown) but pitchedin accordance with the pitch of the coils of the spring 2, and carries atubular housing 56 to prevent the said spring 2 from buckling. The cap48 is secured, as shown, by a hinge 57 to the outer end of the magazine58. The nut 52 in this case takes the place of the pin 16 as thespring-regulating abutment and is turned for varying the number ofspring coils in front of it instead of turning the spring bodily itself.

In one case the power-spring 2 is bodily rotated by the manual rotationof the handgrip 7 whereby the number of coils of the spring in front ofthe fixed pin 16 is increased or diminished, according as it is desiredto increase or diminish the power of the active portion of the spring.In the other case, the power of the said spring 2 is regulated not byrotating the spring bodily by means of the hand-grip 7, but by bodilymoving the individual coils of the spring to one side or the other ofthe nut 52 by manually rotating the nut, which, although free to rotate,does not move with respect to the longitudinal axis of the spring. Inother words, by means of thehand-grip 7, the en-- tire spring is bodilyrotated for changing the number of its coils on the opposite sides ofthe abutment pin 16; while in the other case, without turning the entirespring, certain of its coils are shifted to opposite side of theabutment nut 52. In either case the effect is the same, because thenumber of coils in the active and passive portions of the spring ischanged to give more or less power. Only the coils in front of theabutment, be it the pin 16 or the nut 52, may be said to be in play; theremaining coils are inert because not compressed by the telescop ing ofthe driving and driven members of the device.

I claim 1. In a push drill, the combination with the driving and drivenmembers thereof, of a power spring, a pin engaging with the coils of thespring between the ends thereof and fixed in position with reference tothe longitudinal axis of the drill, and means connected with the outerend of the spring 5 for bodily rotating the same so as to vary loby thebodily rotation of the spring itself.

2. In a push drill, the combination with the driving and driven membersthereof, of a power spring, a housing tube connected with the saiddriving member, a pin carried 15 by the housing tube and extendingtransversely through the said spring, and a hand grip carried by thesaid driving member and connected with the outer end of the spring forthe bodily rotation of the spring with reference to the said pin,whereby the active portion 01' the spring may be lengthened or shortenedby the turning of the hand grip so as to differentiate the number ofcoils of the spring on the opposite sides of the said pin.

In testimony whereof, I have signed this specification in the presenceof two subscribing witnesses.

WILLIAM A. PECK. WVitnesses:

CLARA L. WEED, MALCOLM P. NIoHoLs.

Copies of this patent may be obtained for five cents each, by addressingthe Commissioner of Patents, Washington, D. C.

